John Deere Mower Won’t Turn Over (Find Out Why)

The grass is growing like crazy and once again it’s time to mow the lawn. However, this time you go to start the mower, and nothing happens. Your mower won’t even turn over.

A John Deere mower won’t turn over when the battery is dead or won’t hold a charge; the wires, cables, or connections are loose; the fuse is blown; the ignition switch or safety switch is bad; the starter solenoid is faulty, or the starter is bad.

Be careful working on your lawn mower’s electrical system to avoid electrocution. Follow the safety guidelines found in the operator’s manual. Consult a professional mechanic if you are unsure how to perform troubleshooting and repair procedures.

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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

Troubleshoot: John Deere Mower Won’t Turn Over

• Check for a dead battery
• Look for loose wires and connections or corrosion on the wiring and terminals or bad ground
• Look for a blown fuse
• Check for a bad safety switch
• Check for an ignition switch failure
• Check the starter solenoid
• Have your starter motor tested and replaced if needed

This is Why Your John Deere Mower Won’t Turn Over

Dead or Bad Battery

A John Deere lawn mower won’t turn over when the battery is dead or has a low charge. The first thing you should do is check the battery’s charge using a multimeter.

A fully charged 12-volt battery should give you a reading of about 12.7 volts. If you are getting a lower reading, charge the battery. You can find steps to test a battery in “5 Things That Are Draining the Life of Your Lawn Mower Battery”. Here, you will also find information on what can cause your battery to lose charge.

Charging a Battery: Use a battery charger to charge your battery. Before you continue, wear protective gear to protect your eyes and skin from electrical shock. Follow these steps to charge your John Deere battery with a charger:

• Access the battery and terminals. You may need to use a screwdriver to uncover the battery. Do not remove the battery from the casing.
• Connect the charging cables beginning with the positive cable first. This is the red cable or the one with the plus sign. Place the cable on the positive battery terminal.
• Attach the negative cable to the negative battery terminal. This is the black cable or the one with the negative sign.
• Do not touch anything that doesn’t have a rubber coating to prevent electrocution.
• Set the charger’s voltage and amperage level to the desired level. The average volt level for lawn mower batteries is usually 12 volts. More amperage charges the battery faster. Start with two amps and work up to no more than 10 amps. A slow charge is best.

If the battery fails to hold a charge, the battery must be replaced with a new battery. You can purchase a new battery at your location lawn mower dealership, hardware store, or automotive store.

Bring your old battery with you. Most places will charge you a core fee unless you provide them with your old battery.

Loose Wires and Connections

It’s not uncommon for wires and connections to come loose on a lawn mower. This is because the vibration of the John Deere can cause wires to shake loose so there is no longer good continuity.

In addition to looking for loose wires and making sure they are securely attached, you must inspect the connections and wiring for corrosion. Moisture can cause corrosion that will affect continuity.

Remove the corrosion using a baking soda solution (2 cups water to 3 heaping tablespoons of baking soda). Secure any loose wires and connections.

If you find wires, connections, or terminals are damaged or severely corroded, they must be replaced.

Bad Fuse

You will find a fuse to protect the electrical system. Check the fuse to make sure it isn’t blown.

If you’re unsure if the fuse is blown, you can check it by placing a multimeter probe on each prong of the fuse to measure resistance. A resistance reading near 0 means your fuse is good. An infinity resistance reading indicates a bad fuse.

Replace a blown fuse with a fuse with the same amperage as the fuse you are replacing. Do not use a different amperage.

If you continue to blow fuses, you should bring your mower to your local John Deere mower dealership or lawn mower repair shop to troubleshoot the root cause.

Bad Ignition Switch

The John Deere ignition key switch can be the culprit if you insert the key and turn it to find nothing happens. Your mower will fail to turn over and start.

Check the switch using a multimeter to check continuity to determine if the ignition switch is the problem. To do this, look for the prongs marked “B” for Battery and “S” for Starter Solenoid.

Insert the key and turn it to the start position. With the multimeter set to measure resistance, touch one probe to the B prong and the other probe to the S prong.

A good ignition key switch will measure resistance near 0 ohms. A bad ignition key switch will measure infinite resistance and will need to be replaced.

Bad Safety Switch

There are several safety switches installed designed to keep the operator safe. These switches prevent a mower from starting if certain events are not met like engaging the brake.

A safety switch can be defective and cause a John Deere to fail to turn over. Test your switch using a multimeter. You can also temporarily bypass the safety switch to identify a bad switch but only do this for troubleshooting purposes.

Never operate a mower without the safety switch. Never run a mower when a safety switch is bypassed. A safety switch can save you from serious injury and you never know when you’re going to need it.

Bad Starter Solenoid

The starter solenoid is an electromagnetic switch that initiates the starter motor to turn over John Deere’s engine once it is engaged.

The starter solenoid can fail when the internal spring becomes weak or the copper plate begins to corrode. A starter solenoid failure can also be caused by a weak starter, bad battery, or bad ground.

Before you test your starter solenoid, you must have a fully charged battery. Continue testing the solenoid by using the steps to diagnose a bad starter solenoid in “How to Tell Your Lawn Mower Solenoid is Bad”.

Bad Starter Motor

Once you have ruled out the battery, cables, wiring, ground, and starter solenoid as being the reason your mower won’t turn over, it’s time to look at the starter. The starter can be removed and tested.

I recommend having your local repair shop that specializes in starter and alternator repairs test your starter and rebuild it if possible before just throwing a pricey new starter at your John Deere mower.